Dial-up telecommunication services have been principally concerned with providing circuits between subscribers that are capable of carrying speech, with non-speech traffic being adapted so that it can be carried by the speech circuits. The many signalling protocols, call control and billing methods for the Public Switched Telephony Network (PSTN) have been evolved over many years and now offer a very considerable range of features and facilities. Some other dial-up networks have also been introduced, such as Telex and Packet Switching, which each have their own signalling protocols, call control and billing methods, which give their own features and facilities.
As new dial up services are proposed, either new signalling protocols, call control and billing methods must be introduced, or the existing ones re-used. The object of the present invention is to maximise the opportunity to re-use the existing PSTN signalling, call control and billing methods, thereby greatly reducing the development cycle as well as making it unnecessary to wait for new signalling protocols to be agreed by the standards organisations.
The underlying architecture of what is herein termed "harmonic switching" is suitable for controlling the many new proposed dial-up services, an example of which is Asynchronous Transfer Mode (ATM).